The invention relates to the detection of patients"" susceptibility to arrhythmias and, more particularly, to various techniques for improving the detection of signals to achieve this goal.
There are various devices known in the art for monitoring heart function. Many of these devices typically function by analyzing signals such as an electrocardiogram signal, which can be representative of heart function. There is a need to identify patients at high risk for life-threatening arrhythmias.
Various means have been proposed for detecting patient susceptibility to arrhythmias. U.S. Pat. No. 5,117,834 discloses one method by which pulses of electromagnetic energy are injected into a patient and the changes in the patient""s electrocardiographic signals caused by the injection are recorded. U.S. Pat. No. 5,351,687 is similar in concept to U.S. Pat. No. 5,117,834, but it describes the use of a magnetic sensor for use in detecting the cardiographic signals. U.S. Pat. No. 5,555,888 discloses various means for adapting and automatically facilitating the assessment techniques and means similar to that shown in the above patents for determining patient susceptibility to arrhythmias.
Other techniques which are used to analyze cardiac signals for somewhat similar purposes include those known as t-wave alternans and signal-averaged electrocardiograms. Each of these techniques is limited in its application and utility by various factors which are overcome through use of the below-described inventions.
The present invention provides a system and method of determining, through noninvasive means, a patient""s susceptibility to arrhythmia. More specifically, this invention comprises various improvements to known innovations for optimizing detection of a patient""s susceptibility to arrhythmias. This invention embodies numerous software and sequence improvements for applying this basic technology.
Another purpose of this invention is to provide hardware and signal analysis means for detecting, amplifying, or improving recognition of relevant signals.
Another purpose of this invention is to provide for improved performance lead sets and the software to promote ease of attachment and removal from the patient and ease of connection of the lead system to the hardware.
A further object of this invention is to provide new combinations of electrode placement and use to promote better arrhythmia susceptibility diagnosis.
A further object of this invention is to provide a reduction in the size of necessary components to allow for hand-held system dimensions.
A further object of this invention is to provide a means for distinguishing between the signals from the X, Y, and Z directions as well as previously unused directional components of very low-level signal data.
Another object of this invention is to supply means for displaying of a patient""s waveforms and other data derived from the detected signals, as well as to provide various interfaces to communicate the data between the patient and physician or health care professional.
It is a further object of this invention to provide signal artifact reduction, and to provide a single point connector for the set of leads.
Another object of this invention is to provide improved lead materials for improved performance, as well as an improved lead effect modeling (LEM).
It is yet another object of this invention to provide amplifier circuitry that minimizes amplifier saturation and optimizes fast recovery.